rjsilva Posted November 21, 2009 Share Posted November 21, 2009 I arrived home this evening and noticed a buzz/hum coming from my RB-75s - and they aren't plugged in! I moved one around the house and the only thing that seemed to make a difference was the direction it was pointing. Wouldn't there have to be a serious radio/magnetic (not that I know) transmission to cause something like that? Is that legal? I recently moved here last week, but this is the first it's happened. Any ideas? Thanks! Quote Link to comment Share on other sites More sharing options...
Oblio Posted November 21, 2009 Share Posted November 21, 2009 Transmission line overhead ? Quote Link to comment Share on other sites More sharing options...
rjsilva Posted November 21, 2009 Author Share Posted November 21, 2009 No transmission lines that I can see. There are some very large radio antennas a couple of miles away, but that's all I can think of. But wouldn't either of those cause regular buzzing? Quote Link to comment Share on other sites More sharing options...
rjsilva Posted November 21, 2009 Author Share Posted November 21, 2009 I discovered it! It was a downstairs dimmer switch that wasn't all the way up controlling a light that had CFL bulbs. Amusing, but scary that it can generate so much electromagnetic energy. Quote Link to comment Share on other sites More sharing options...
Oblio Posted November 21, 2009 Share Posted November 21, 2009 No transmission lines that I can see. There are some very large radio antennas a couple of miles away, but that's all I can think of. But wouldn't either of those cause regular buzzing? In theory, no, much too far away and the wrong frequency. A bad connection in the speaker/crossover (providing the requisite nonlinear transfer function) might demodulate the carrier but I highly doubt it. Quote Link to comment Share on other sites More sharing options...
Oblio Posted November 21, 2009 Share Posted November 21, 2009 I discovered it! It was a downstairs dimmer switch that wasn't all the way up controlling a light that had CFL bulbs. Amusing, but scary that it can generate so much electromagnetic energy. So much for my poo-pooing of twisted pair speaker wires. Quote Link to comment Share on other sites More sharing options...
jerohm Posted November 22, 2009 Share Posted November 22, 2009 ... Amusing, but scary that it can generate so much electromagnetic energy. just think of the implications that 10-20 years may hold, with all the people running around with cell phones glued to their temples. Quote Link to comment Share on other sites More sharing options...
wuzzzer Posted November 22, 2009 Share Posted November 22, 2009 I was transporting my Forte IIs in the back of my wife's car once and could hear a buzzing sound that drove me nuts. Found it was coming from the speakers even though they weren't hooked up to anything. One of the Klipsch employees on here had a name for the Fortes because apparently they used to do that a lot even though they weren't hooked up. Quote Link to comment Share on other sites More sharing options...
LarryC Posted November 22, 2009 Share Posted November 22, 2009 Most likely EMI reaching the crossover coils or driver voice coils. As I understand it, EM interference falls off with at least the square of the distance from the offending EM emitter, which could, for example, be in the basement directly under the speaker. Quote Link to comment Share on other sites More sharing options...
Islander Posted November 22, 2009 Share Posted November 22, 2009 I was transporting my Forte IIs in the back of my wife's car once and could hear a buzzing sound that drove me nuts. Found it was coming from the speakers even though they weren't hooked up to anything. One of the Klipsch employees on here had a name for the Fortes because apparently they used to do that a lot even though they weren't hooked up. Sounds like free power. I wonder if it could light up a light bulb? Is there something unusual about the Forte crossovers that lets them pick up stray EMF more effectively than any other speaker? Could a small "power collector" be built using similar but simpler components? I say simpler because it would not need to control any drivers, just capture energy from its surroundings. Quote Link to comment Share on other sites More sharing options...
jerohm Posted November 22, 2009 Share Posted November 22, 2009 When I was working on my center, I had a Quartet sitting on its side directly on top of my (tube) TV which did the same thing. If the amplifer was fired up however, the buzzing would stop. PS: WUZZZER, I think my pointer is in LOVE. Quote Link to comment Share on other sites More sharing options...
Don Richard Posted November 24, 2009 Share Posted November 24, 2009 It is more likely a low frequency mechanical vibration from an air conditioning/heating unit, A/C vent, or subway or something. We have such a mechanically coupled buzz coming from a telephone hung on the wall in our office, from the HVAC nearby. At my house I have an intermittent rattle coming from a window when the A/C is running. A voltmeter set to alternating current millivolts hooked to the speaker input terminals will show if the speaker cones are vibrating from such a cause and generating any voltage caused by air pressure variations moving the cones or mechanical coupling shaking them. Any dynamic loudspeaker can thus be used as a crude microphone, with varying results. If you are indeed getting enough induced voltage to cause cone movement, there are serious issues, maybe a high powered TV or radio transmitter nearby. This is not good for noise pickup with your electronics, and maybe not healthy for you and yours. Quote Link to comment Share on other sites More sharing options...
Klipsch Employees Trey Cannon Posted November 25, 2009 Klipsch Employees Share Posted November 25, 2009 do you have a TV in the room with a picture tube? I have seen this before in many Klipsch speakers. the flyback transformer on the TV is going bad and the crossover in the speaker acts like a radio and picks it up. The drivers are so effecient that they will play the noise loud enough for us to hear... If not the TV then something close doing the same thing. Dimmers can do that... Get a better dimmer or keep the music playing... Quote Link to comment Share on other sites More sharing options...
Don Richard Posted November 25, 2009 Share Posted November 25, 2009 do you have a TV in the room with a picture tube? I have seen this before in many Klipsch speakers. the flyback transformer on the TV is going bad and the crossover in the speaker acts like a radio and picks it up. The drivers are so effecient that they will play the noise loud enough for us to hear... If not the TV then something close doing the same thing. Dimmers can do that... Get a better dimmer or keep the music playing... Good info, Trey. I wasn't aware these dimmers could put out enough RFI/EMI to be detected by a disconnected loudspeaker. Another argument in favor of bi or triamping [] Quote Link to comment Share on other sites More sharing options...
Klipsch Employees Trey Cannon Posted November 25, 2009 Klipsch Employees Share Posted November 25, 2009 NO Don...you have it all wrong...more speakers not more amps... BTW: you could build a block for the EMF or RF but it would also block music... Maybe cover the network with copper plate to block the siginal from getting in...but that would also be hard to do. Quote Link to comment Share on other sites More sharing options...
Marvel Posted November 26, 2009 Share Posted November 26, 2009 This is what you need. You can get it in thin sheets, and make a cover for the crossovers. http://www.mumetals.com/faqs.html Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.